THIS IS A SHANNON AWARD PROVIDING PARTIAL SUPPORT FOR THE RESEARCH PROJECTS THAT FALL SHORT OF THE ASSIGNED INSTITUTE'S FUNDING RANGE BUT ARE IN THE MARGIN OF EXCELLENCE. THE SHANNON AWARD IS INTENDED TO PROVIDE SUPPORT TO TEST THE FEASIBILITY OF THE APPROACH; DEVELOP FURTHER TESTS AND REFINE RESEARCH TECHNIQUES; PERFORM SECONDARY ANALYSIS OF AVAILABLE DATA SETS; OR CONDUCT DISCRETE PROJECTS THAT CAN DEMONSTRATE THE PI'S RESEARCH CAPABILITIES OR LEAD ADDITIONAL WEIGHT TO AN ALREADY MERITORIOUS APPLICATION. THE APPLICATION BELOW IS TAKEN FROM THE ORIGINAL DOCUMENT SUBMITTED BY THE PRINCIPAL INVESTIGATOR. The long term goal of this work is to develop more effective gene therapy strategies for inborn errors in metabolism. Lysosomal storage diseases are heritable disorders generally caused by the lack of an acid hydrolase and are good candidates for gene therapy. Mucopolysaccharidosis type VII (MPS VII or Sly Syndrome) is a sever form of lysosomal storage disease caused by a lack of (beta-glucuronidase activity and results in skeletal deformities, mental retardation and early death. Murine MPS VII has been treated with varying degrees of success by bone marrow transplantation (BMT), direct recombinant enzyme replacement, and somatic cell gene therapy techniques. Allogeneic BMT in humans with MPS VII results in variable correction of the disease and although enzyme replacement in the MPS VII mouse corrects much of the pathology, including that observed in the central nervous system, this form of therapy will be very expensive and require administration throughout life. Somatic cell gene therapy techniques have resulted in partial correction of the histologic alterations in mice with MPS VII and may provide an effective means of treatment for this form of disease in humans. However, in most cases, gene transfer techniques have resulted in very low levels of expression from either reporter genes or therapeutic genes such as (beta- glucuronidase. The specific goal of this work is to develop an amplification system based on bacteriophage T7 RNA polymerase for use as a gene therapy tool for MPS VII. The system will initially be characterized in vitro in (beta-glucuronidase deficient fibroblasts and then in vivo in MPS VII mice to determine the effectiveness of this system to produce therapeutic amounts of recombinant enzyme. This proposal will be accomplished by the following specific aims: 1. We will determine the optimum promoter-T7 RNA polymerase gene combination resulting in overexpression of beta-glucuronidase from the beta-glucuronidase cDNA regulated by the T7 promoter. 2. We will determine the conditions required for efficient transcription from a single plasmid containing the T7 RNA polymerase gene and beta- glucuronidase cDNA driven by the T7 promoter. 3. We will determine the effectiveness of the amplification system to treat murine MPS VII when delivered to hematopoietic stem cells by a retrovirus or systematically by cationic liposomes.